Re: Adding skip scan (including MDAM style range skip scan) to nbtree
Tomas Vondra <tomas@vondra.me>
Commits
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the thread's linked commits as JSON, with link sources.
API reference →
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nbtree: Always set skipScan flag on rescan.
- 454c046094ab 19 (unreleased) landed
- bee763aea13f 18.0 landed
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meson: Build numeric.c with -ftree-vectorize.
- 9016fa7e3bcd 19 (unreleased) cited
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Fix "variable not found in subplan target lists" in semijoin de-duplication.
- b8a1bdc458e3 19 (unreleased) cited
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Revert "nbtree: Remove useless row compare arg."
- dd2ce3792754 18.0 landed
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nbtree: Remove useless row compare arg.
- 54c6ea8c81db 18.0 cited
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Prevent premature nbtree array advancement.
- 5f4d98d4f371 18.0 landed
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nbtree: tighten up array recheck rules.
- 7e25c9363a82 18.0 landed
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Avoid treating nonrequired nbtree keys as required.
- 0f08df406822 18.0 landed
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Adjust overstrong nbtree skip array assertion.
- 9d924dbb3710 18.0 landed
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Make NULL tuple values always advance skip arrays.
- b75fedcab791 18.0 cited
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Avoid extra index searches through preprocessing.
- b3f1a13f22f9 18.0 landed
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Improve nbtree skip scan primitive scan scheduling.
- 21a152b37f36 18.0 landed
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Further optimize nbtree search scan key comparisons.
- 8a510275dd6b 18.0 landed
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Add nbtree skip scan optimization.
- 92fe23d93aa3 18.0 landed
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Improve nbtree array primitive scan scheduling.
- 9a2e2a285a14 18.0 landed
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nbtree: Make BTMaxItemSize into object-like macro.
- 426ea611171d 18.0 landed
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Show index search count in EXPLAIN ANALYZE, take 2.
- 0fbceae841cb 18.0 landed
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Make parallel nbtree index scans use an LWLock.
- 67fc4c9fd7fa 18.0 landed
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Show index search count in EXPLAIN ANALYZE.
- 5ead85fbc811 18.0 landed
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Avoid nbtree parallel scan currPos confusion.
- b5ee4e52026b 18.0 cited
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nbtree: Remove useless 'strat' local variable.
- b6558e4f837e 18.0 landed
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Normalize nbtree truncated high key array behavior.
- 79fa7b3b1a44 18.0 landed
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Refactor handling of nbtree array redundancies.
- b524974106ac 18.0 landed
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Fix nbtree pgstats accounting with parallel scans.
- c00c54a9ac1e 18.0 landed
- fb4f5e58af97 17.0 landed
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Avoid parallel nbtree index scan hangs with SAOPs.
- d8adfc18bebf 18.0 landed
- a24bffc021d9 17.0 landed
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Show Parallel Bitmap Heap Scan worker stats in EXPLAIN ANALYZE
- 5a1e6df3b84c 18.0 cited
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Enhance nbtree ScalarArrayOp execution.
- 5bf748b86bc6 17.0 cited
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Skip checking of scan keys required for directional scan in B-tree
- e0b1ee17dc3a 17.0 cited
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Instead of using a numberOfRequiredKeys count to distinguish required
- 7ccaf13a06b8 8.2.0 cited
On 9/12/24 16:49, Matthias van de Meent wrote: > On Mon, 9 Sept 2024 at 21:55, Peter Geoghegan <pg@bowt.ie> wrote: >> > ... > > The fix in 0001 is relatively simple: we stop backends from waiting > for a concurrent backend to resolve the NEED_PRIMSCAN condition, and > instead move our local state machine so that we'll hit _bt_first > ourselves, so that we may be able to start the next primitive scan. > Also attached is 0002, which adds tracking of responsible backends to > parallel btree scans, thus allowing us to assert we're never waiting > for our own process to move the state forward. I found this patch > helpful while working on solving this issue, even if it wouldn't have > found the bug as reported. > No opinion on the analysis / coding, but per my testing the fix indeed addresses the issue. The script reliably got stuck within a minute, now it's running for ~1h just fine. It also checks results and that seems fine too, so that seems fine too. regards -- Tomas Vondra